The identification of various kinds of tissues is based on their response both to an electrical stimulus and the response to light incidence. There are currently many apparatus and techniques for identifying different kinds of tissues, both normal and tissues infected with human papilloma virus, precancerous and cancerous. Many Optical principles exist which are already tested for identifying tissues such as Spectroscopic Fluorescence, Raman Spectroscopy and OCT. On other hand biological tissues have a characteristic electrical impedance which is related to the frequency in that the tissue has components having both resistive and charge storing (capacitive) characteristics. Impedance magnitude and its dependence on the frequency are a function of the tissue composition.
The starting point of this invention focuses in the fact that no uterine cervical cancer detection method displays a sufficiently precise reliability, which gives a high risk of an erroneous diagnosis, this turning into a very important matter if we understand that this type of cancer can be cured if it detected at an early stage, otherwise being mortal.
The conventional Papanicolau or uterine cervical cancer testing has been practically the same since about 60 years. Since 1940 the death percentage in women having cervical cancer has decreased 70%, mainly because many women undergo Papanicolau testing or uterine cervical cancer tests. Although not infallible, this test detects 95% of cervical cancers and, more importantly, it detects them in a state which is not visible to the naked eye yet and, therefore, they can be treated and almost invariably cured. Despite the increase in worldwide opportune uterine cervical cancer detection campaigns by the Papanicolau testing, in some countries, specially those of the third world or undeveloped ones, there are still strong cultural and psychological barriers in women and occasionally in their couples which cause women not to undergo a Papanicolau testing.
Among some of these barriers there are wrong beliefs, fear to obtain an adverse result, to the pain in the examination or shyness as the examination could be undertaken by a male person or in the presence of strange persons in an assisting facility.
Currently there has been uncountable optical, electrical and biomedical research, and further each one of them has different variants. For instance the review article “Relation between tissue structure and imposed electrical current flow in cervical neoplasia” relates to studies performed on the cervix tissue reaction when electrical pulses are applied at different frequency ranges. This article discloses a thorough research of every part intervening in this invention, particularly on the electrical measurement, optical measurement, the electronics inside the device and the assembly materials.
Inventions currently exist that use electrical impedance measurement from tissue. Representative patents are: U.S. Pat. No. 4,458,694, “Apparatus and method for detection of tumors in tissue”; U.S. Pat. No. 5,353,802, “Device for measurement of electrical impedance of organic and biological materials”; U.S. Pat. No. 5,361,762, “Apparatus for detecting properties, differences and changes of humans or animals bodies”; and U.S. Pat. No. 6,026,323, “Tissue diagnostic system”. In relation to the optical part based on the methods of light reflection from tissues the representative patents are the following: U.S. Pat. No. 4,930,516, “Method for detecting cancerous tissue using visible native luminescence”; U.S. Pat. No. 5,503,853, “Use of light conveyed by fiber optics to locate tumors. Physiological probe”; U.S. Pat. No. 5,439,000, “Method of diagnostic tissue with guidewire”, and U.S. Pat. No. 6,026,323, “Tissue diagnostic system”.
With respect to self-detection devices, some important inventions have been found. U.S. Pat. No. 3,995,618 to Kingsley et al. claims a cervical sample collecting device which can be self-administered comprising an outer tube and an inner tube telescopically positioned inside the outer tube, a wet cervical sponge having a setting solution and mounted in the front end portion of the inner tube and projecting outwardly from it and a protecting sleeve which surrounds the inner tube and the cervical sponge before and after its insertion into the vagina.
U.S. Pat. No. 5,231,992 claims a device for self-obtaining cervix cell and fluid samples comprising a cervical cell and fluid collector, formed of a disc shaped body manufactured from a polyurethane foam which is placed in the patient's cervix and fluids and cells adhere to the device walls.
U.S. Pat. No. 6,155,990 to Fournier claims a device for auto-sampling culture material or specimens used in cytological or microbiological study techniques, which comprises a cardboard tube housing a retractable sponge that includes a grip adapted for serving as a screwable cap for sealing and preserving a sample within a tube.
U.S. Pat. No. 6,302,853 to Sak, Robert F. claims a device and method for collecting cervical tissue samples comprising an insertion tube and an introduction guide member which guides the insertion tube into the vaginal cavity. A cervical sample collector is included that is positioned inside the vaginal insertion tube and extends into the vaginal cavity for collecting the sample, which has to be rotated until completing a revolution.
U.S. Pat. No. 6,402,700 to Richards, claims an personal apparatus and method for taking cervical cell samples that includes an insertion handle, a flexible speculum ring and means for movably attaching the speculum ring to the insertion handle. The speculum ring includes two adjacent ring halves circumferentially divided in order to allow the expansion of the speculum tube housed inside the hollow ring halves. The method comprises inserting the flexible speculum assembly inside user's vagina, moving the speculum ring into a raised position surrounding the cervix, separating the ring halves for expanding the tube, defining an speculum aperture and inserting a sampling tool through the orifice until it contacts the cervix or the surface of the areas adjacent thereto.
Australian Patent No. A61B 10/00 discloses a device for cervical tissue sample collection comprising a cylindrical barrel with an inner shaft. Said shaft has in its one end a circular brush and a sponge. The device is introduced in the vagina, and once it is inside the shaft is pushed and the end is rotated. The sponge and brush will collect a sample of the tissues. Once the process has ended, the shaft end wherein the brush and sponge are located can be detached and sent to analysis.
British Patent No. GB 2159240 teaches a method for obtaining cervical canal cells by inserting a conical shaped brush for trapping the cells therein.
The main disadvantage of these devices claimed by all the above disclosed patents resides in the fact that the user cannot achieve a correct localization of the cervix, therefore the sample is taken from wrong places consequently obtaining very poor quality samples which are inadequate for their analysis, thus causing the need of repeating the test or that the user has to attend an specialist.
From the above disclosure, a need has been found for having a device which relies in the correct positioning and locating of the cervix and that also does not always uses an invasive method based on the retrieval and sample collection of the cervix, and that this new device by means of an accurate localization of the cervix performs simultaneous electrical and optical tissue measurements, and in the case of the test resulting positive to cancer this same device by means of an attachment retrieves the tissue samples in order for them to be sent to a laboratory and follow the common procedure. Other advantage of this invention is that the user has the choice of performing the detection test without requiring the presence of a skilled physician.